Zone not working in Oil Boiler system

cfricker

Anyone that works on these kind of furnaces please chime in.

Details:

Oil Fired Hot Water Baseboard Heating

I've got two zones. One is working and one isn't. I've tested the thermostat and confirmed it is calling for heat. I've swapped out the motors on the zone valves as I had an extra one kicking around. I've manually tried to move the lever on the bottom and it is loose/easily moves indicating that the motor has moved the actuator (don't know if this is the correct term). At this point I'm thinking the end zone switch is bad. But then again the end zone switch fires up the circulator, correct? So if my other zone is running and has already activated the circulator shouldn't I be getting warm water past the zone valves? All conditions seem to be met that would indicate the valve to be open.

I was just about to swap out the end zone switch when thinking about this. Now I'm kind of lost at where to go from here. Any thoughts? It is a Honeywell older zone valve.

Update:

I started to believe maybe I had a frozen line. It's been pretty cold lately and I use a heat pump so this zone doesn't run very often. I manually opened the valve and set my other working zone to run and circulate. I then closed off an isolation valve that is just a couple feet past the zone valve and waited for the pipe to heat up. It will not heat up. There must be no water getting through the valve but don't these things for sure open when you open manually? I feel the resistance as I pull the lever and lock it in place.

If the line was frozen somewhere I still would have gotten heat a couple feet past the zone valve. I'm thinking the valve has to be stuck even after doing it manually, but is this possible?

I'm an electrician by the way so I'm good with the electrical side of things and pretty handy at troubleshooting. Need to hear from a furnace pro at this point so I can sleep tonight haha.

HVACNUT

Its either frozen or air bound.
If you try to purge the loop and no water comes out then its time to get a hair dryer and find the draft(s). Then insulate.